Question

Amphids for olfacto-reception are present in Ascaris on

• A. Pre-anal papilla
• B. Post-anal papilla
• C. Dorsal lip
• D. Ventrolateral lips

Answer 1

The correct option is D Ventrolateral lips

Ascaris' triangular mouth is surrounded by one mid-dorsal and two ventrolateral lips. The dorsal lip has two double sensory papillae and ventrolateral lip carries one double sensory papilla each. The ventrolateral lips also have a lateral papillae each and a chemoreceptor called amphid. There is a pair of cervical papillae and a pair of cephalic papillae on the dorsal side of the head.

So, the correct answer is 'Ventrolateral lips'.